Quick Thermostat Wiring Question

[adzyp]

Hi, im looking to change my CH thermostat to a wireless system and hoping to just do a straight swap with the box that is already on the wall.

Im looking at the wiring diagrams but cant really match them up.

This is what I have wired up at the moment:

and this is what im looking to replace it with:

Is this doable and easy enough? I am usually quite handy around the house so am quite good at these things usually, im just struggling to match the 2 up fro the diagrams[/img]

 

[EFLImpudence]

A = 1
B = 3

The whole point of the wireless system is so that the receiver is near the boiler or wiring centre and a cable to the thermostat position is not necessary.

If you do not have a neutral or the boiler control is not 230V at the present position, you will have to put it near the boiler or wiring centre and not use the existing cable.

 

[adzyp]

Thanks for your reply.

Let me explain the situation a little more. At present I have the combi in the 3rd bedroom and the current wired thermostat is on the wall outside the door. This is why I want a wireless one so that I can have the thermostat downstairs as i dont agree with it being on the landing, there is only a small radiator at the bottom of the stairs so the boiler is constantly working to try and reach the temperature.

I was hoping to just do a straight swap out with the thermostat thats currently on the wall with the new receiver then locate the wirleess thermostat downstairs.

Just to add to the second diagram, it is also saying "T710R only: Note that the output contacts are voltage- free, so power needs to be put on to Terminal 1 either by linking from Terminal L or from a separate supply with a 3A fuse"

can that just be as simple as putting a wire from Terminal 1 to Terminal L like you do on light switches?

 

[JohnW2]

I was hoping to just do a straight swap out with the thermostat thats currently on the wall with the new receiver then locate the wirleess thermostat downstairs.

As EFLI said, your problem there will be that there is not currently a neutral, and possibly not a line/live (if the switching is not 230V), available at the thermostat position. As he said, your best bet would be to install the new stat close to the CH 'wiring centre' (or whatever), disconnecting the feed to the present thermostat.

Just to add to the second diagram, it is also saying "T710R only: Note that the output contacts are voltage- free, so power needs to be put on to Terminal 1 either by linking from Terminal L or from a separate supply with a 3A fuse" can that just be as simple as putting a wire from Terminal 1 to Terminal L like you do on light switches?

Assuming the switching is at 230V (which would need to be confirmed), you would need to find out which of L1 and L2 from the boiler (A & B of your present stat) is the 'permanent live' and connect that to T1 (current A), and the other one to T2 (current B), and then also link T1 to L, as in the diagram. However, that would still leave you needing a neutral, which you don't have at the current stat position - so, as above, I think you need to consider a different location for it.

[/quote]

 

[adzyp]

I was hoping to just do a straight swap out with the thermostat thats currently on the wall with the new receiver then locate the wirleess thermostat downstairs.

As EFLI said, your problem there will be that there is not currently a neutral, and possibly not a line/live (if the switching is not 230V), available at the thermostat position. As he said, your best bet would be to install the new stat close to the CH 'wiring centre' (or whatever), disconnecting the feed to the present thermostat.

Just to add to the second diagram, it is also saying "T710R only: Note that the output contacts are voltage- free, so power needs to be put on to Terminal 1 either by linking from Terminal L or from a separate supply with a 3A fuse" can that just be as simple as putting a wire from Terminal 1 to Terminal L like you do on light switches?

Assuming the switching is at 230V (which would need to be confirmed), you would need to find out which of L1 and L2 from the boiler (A & B of your present stat) is the 'permanent live' and connect that to T1 (current A), and the other one to T2 (current B), and then also link T1 to L, as in the diagram. However, that would still leave you needing a neutral, which you don't have at the current stat position - so, as above, I think you need to consider a different location for it.

[/quote]

Ahh man, ok thank you for your reply.

I was hoping this was going to be a straight forward swap and wouldn't have to get an electrician in

Im not sure i can do any of what you have suggested myself

 

[JohnW2]

Ahh man, ok thank you for your reply. ... I was hoping this was going to be a straight forward swap and wouldn't have to get an electrician in Im not sure i can do any of what you have suggested myself

You're welcome - and, yes, it's potentially a bit complicated.

Your best bet would probably have been to get a battery-operated wireless stat, which would then probably just need to be connected to the two wires (A & B) at your present stat position.

Kind Regards, John

 

[adzyp]

Ahh man, ok thank you for your reply. ... I was hoping this was going to be a straight forward swap and wouldn't have to get an electrician in Im not sure i can do any of what you have suggested myself

You're welcome - and, yes, it's potentially a bit complicated.

Your best bet would probably have been to get a battery-operated wireless stat, which would then probably just need to be connected to the two wires (A & B) at your present stat position.

Kind Regards, John

Thanks. Im a bit confused now then, I thought all wireless thermostat systems were the same. The link to the one ive ordered is below:

http://www.screwfix.com/p/drayton-m... and Cooling&gclid=CInf8e2omcICFTDJtAodmW4ADg

Are they not all like this? A wall mounted box and then a battery operated portable thermostat?

 

[EFLImpudence]

Yes, they are all similar to each other but not to your present thermostat.

 

[adzyp]

Yes, they are all similar to each other but not to your present thermostat.

Ok, so regardless of which wireless thermostat I buy, I am going to have the same problem?

How much do you think I would be looking at for a sparky to fit this?

 

[adzyp]

This is an alternative one by the same make. Is this the same situation?

Just looks a bit different and it does also say "This product is double insulated and does not require an earth connection. The MiStat R should be wired to the boiler or central heating wiring using the correct type of cable or flex. The MiStat R should be wired to replace hard wired room or programmable thermostats, as shown on the system or boiler wiring diagrams."

 

[JohnW2]

Yes, they are all similar to each other but not to your present thermostat.

You say that but, as I suggested, aren't there ones with battery-powered 'master' units (as well as battery-powered sensor units) - probably designed specifically to address the OP's situation (no neutral, and possibly even no L, available).

Kind Regards, John

 

[JohnW2]

This is an alternative one by the same make. Is this the same situation?

Unfortunately, that raises the same issues. As I said, what you really need to try to find (I'm pretty sure that they exist!) is one for which the main/master unit is battery-powered - you would then be able to simply replace you present stat with it.

Kind Regards, John

 

[JohnW2]

As I said, what you really need to try to find (I'm pretty sure that they exist!) is one for which the main/master unit is battery-powered - you would then be able to simply replace you present stat with it.

How about (this one), instructions (here) - which I think is probably an example of what I was talking about?

Kind Regards, John

 

[adzyp]

I see. I wasn't aware my current one had batteries in to be honest! I just took the front off to have a look:

So lets say, I move the new one next to the boiler, can that be a DIY job with basic experience?

 

[adzyp]

Sorry, one more final thing ive just thought of. Right next to this thermostat on the wall is the burglar alarm box, can the supply to that be of any use? Not sure how I would get to the wires though